For a variety of medical ailments it is desirable to leave a catheter in place within a patient for an extended period of time. A catheter may be left in place, for example, to permit periodic blood transfusions, to perform renal dialysis, or to permit the periodic administration of antibiotics, chemotherapy treatment, or TPN (total parenteral nutrition).
The type of indwelling catheter used is dictated by a variety of circumstances such as the condition being treated, individual patient characteristics and requirements, and the expected duration for which the catheter will remain in place. Under certain circumstances, it is desirable to use a catheter such as a PORT-A-CATH that is completely embedded under the skin. This type of catheter can be accessed periodically by inserting a needle through the skin and into an access port of the catheter. The risk of infection is relatively low for this type of catheter since no portion of the catheter resides outside of the body, and since no puncture site is required when the catheter is not being accessed.
For some applications in which the catheter will remain in place for a relatively short term, it is often desirable to use a percutaneous catheter. This type of catheter has a distal end that is located inside the body (for example, within the superior vena cava in patients being treated for certain types of cancer) and a proximal end that is located outside the body.
Indwelling, percutaneous catheters have the disadvantage of extending through a puncture site which can serve as a portal for infectious agents such as bacteria, fungi and viruses to enter into the system. Patients that use this type of catheter must, therefore, take extraordinary precautions to keep the proximal end of the catheter and the region surrounding puncture site in a clean condition. In particular, such patients typically must refrain from swimming, showering and similar contacts with fluids. There is therefore a need to provide a means for shielding both the proximal end of a percutaneous catheter and the puncture site from fluids or other media that may contain infectious agents.